P3536 - Serological Responses to SARS-CoV-2 Vaccination in Patients with Inflammatory Bowel Disease Are Impaired for Those on Anti-TNF and Immunomodulator Combination Therapy

Kenneth Ernest-Suarez, MD¹, Catherine Rowan, MD¹, Joshua Quan, MSc¹, Fiona Yeaman, MBBS¹, Christopher Ma, MD², Remo Panaccione, MD¹, Lindsay Hracs, PhD¹, Nastaran Sharifi, MD¹, Michelle Herauf, MSc¹, Ante Markovinović, BA¹, Stephanie Coward, PhD¹, Joseph W.. Windsor, PhD¹, Léa Caplan, BHSc¹, Richard J. M.. Ingram, MD, PhD¹, Cynthia Seow, MD¹, Kerri Novak, MD¹, Cathy Lu, MD, MSc¹, Gilaad G. Kaplan, MD, MPH^1
1University of Calgary, Calgary, AB, Canada; ²Alimentiv Inc., University of Calgary, London, ON, Canada

Introduction: Anti-tumor necrosis factor (TNF) reduces the serological responses (SR) to SARS-CoV-2 vaccination and impairs SR durability within individuals with IBD.^1-3 Additional doses of SARS-CoV-2 vaccination effectively increase antibody titers in patients treated with anti-TNF agents, responses are still lower compared to healthy controls.^{4 5} Data comparing serological responses between anti-TNF monotherapy and combination therapy are lacking. This study aims to compare serological responses from SARS-CoV-2 vaccination between IBD patients treated with anti-TNF monotherapy or combined with an immunomodulator.

Methods: Adults with IBD, at least two doses of a SARS-CoV-2 vaccine, with anti-TNF monotherapy (anti-TNF alone) or combination therapy (anti-TNF in addition to methotrexate or azathioprine) were recruited through the STOP COVID-19 in IBD cohort.⁵ Serum samples were drawn for assessment of IgG antibodies to the spike protein of SARS-CoV-2 (anti-S) using the Abbott Architect SARS-CoV-2 IgG II Quant assay following 1–8 weeks after 1^st dose vaccination, and both 1­–8 weeks and 8+ weeks after 2^nd, 3^rd, and 4^th dose vaccination. Demographic and medication status information was collected through chart review. SR was defined as IgG levels of ≥50 AU/mL; positive SR rates were compared between medication groups using two-sample proportion tests. Anti-S concentrations were reported as geometric mean titres (GMT) with 95% confidence intervals and were compared between medication groups using Mann Whitney-U tests.

Results: 207 patients on anti-TNF monotherapy and 68 on combination therapy were recruited. Anti-S titres were significantly decreased for individuals on combination therapy compared to anti-TNF monotherapy 1­–8 weeks after 1^st dose vaccination, and both 1–8 weeks and 8+ weeks after 2^nd dose vaccination. No significant differences in GMTs were determined between anti-TNF monotherapy and combination therapy groups following all timepoints after additional dose vaccination (Table 1, Figure 1).

Discussion: IBD patients treated with combination therapy develop a significantly reduced serological response to a two-dose SARS-CoV-2 regimen compared to those with anti-TNF monotherapy. These differences are no longer observed following additional vaccine doses and both medication groups develop robust antibody responses. These findings highlight the importance of additional doses for adequate serological protection within the IBD population and especially for those on anti-TNF combination therapy.



Disclosures:


Kenneth Ernest-Suarez, MD¹, Catherine Rowan, MD¹, Joshua Quan, MSc¹, Fiona Yeaman, MBBS¹, Christopher Ma, MD², Remo Panaccione, MD¹, Lindsay Hracs, PhD¹, Nastaran Sharifi, MD¹, Michelle Herauf, MSc¹, Ante Markovinović, BA¹, Stephanie Coward, PhD¹, Joseph W.. Windsor, PhD¹, Léa Caplan, BHSc¹, Richard J. M.. Ingram, MD, PhD¹, Cynthia Seow, MD¹, Kerri Novak, MD¹, Cathy Lu, MD, MSc¹, Gilaad G. Kaplan, MD, MPH¹. P3536 - Serological Responses to SARS-CoV-2 Vaccination in Patients with Inflammatory Bowel Disease Are Impaired for Those on Anti-TNF and Immunomodulator Combination Therapy, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.